You can wait for hours, days or months for the right sky and still be disappointed. But don't get too downhearted as a little bit of digital processing will give your image the sky it needs.
Before we get to this stage we need a sky to import and having a library of stormy, bright blue and sunset-coloured skies is a time saving idea that's practical and easy to create. In other words, just shoot interesting skies whenever you see one and do so with wide-angle, standard and telephoto lenses. Also, consider the many varieties of lighting - back, frontal, side, for example - so you build a library of sky images to cover all creative options.
For most skies in the open all you need is a wide-angle or standard zoom lens but a long telephoto lens can be useful too. If you're planning on taking several images of the sun LiveView is crucial as you don't want to be looking down the lens with it burning back into your eyes. A strong neutral density filter will help reduce the sun's glare and a polariser is perfect for creating saturated blue skies.
Usually you're told to remove some of the sky but this time it's our focus so you want to shoot from a position that allows you to get plenty of it in frame and be in a location where there's no distracting objects such as trees, buildings and long grasses. Pay attention to which direction the light is coming from and note it down as you don't want to use a sky with light coming from the left when shadows on your original image lay in the opposite direction. Don't ignore the clouds either as they can alter the light and make certain areas of the shot darker than others. For sunsets, which work well dropped into shots of people or buildings silhouetted, you need to fill the shot with the sun but don't stare at it through the lens as this will damage your eyes. Use LiveView, point and press. Stormy skies are perfect for atmospheric shots where castles or any other old building are your centre piece. Watch for breaks in the clouds where long streaks of sunlight burst through for more interesting images.
For more tips on replacing skies or shooting images where they sky is your main focus, have a look at these tutorials:
For more information on the Olympus OM-D E-M10 visit the Olympus website.